The present invention relates to a conveyor support way for a table top chain, and more particularly to a conveyor support way utilizing a pair of replaceable wear strips disposed in serpentine fashion along the length of the support way.
A conveyor using "table top" type chain typically includes a conveyor return support way designed to support the unloaded chain as it is transported from the back end of a conveyor to the front end of the conveyor. Such a conveyor support way is desirably provided with replaceable wear strips of low friction material so that, as the wear strips wear out due to the friction involved as the chain passes over the strips, the strips are easily replaced. While wear strips have been provided in numerous configurations in the past (for example, as a slider bed, series of rollers, etc.), the most desirable pattern has been a pair of round or rectangular strips of material which wind from one end of the conveyor support way to the other in a "serpentine" configuration. In order to maintain the wear strips in the desired serpentine configuration, the wear strips have typically been bolted or otherwise fastened to cross members disposed in spaced relationship along the length of the return way.
While the technique of bolting serpentine wear strips to cross members appropriately positioned along the length of the conveyor support way has proven to be useful where the wear strips are formed of material having a low thermal coefficient expansion, it has not proven to be entirely satisfactory. In particular, the bolting technique is not useful where the wear strip is composed of a material having a high thermal coefficient of expansion. It will be recognized that when a strip of material is fixedly secured between two stationary members and is then heated, the resultant expansion of material must evidence itself in some manner, typically either by an increased lateral curvature of the serpentine wear strip (thus depriving the chain of support in the intended places) or, more importantly, in a vertical buckling of the serpentine wear strip (thus depriving the chain of the desired support along its full length). Accordingly, various plastic materials with high thermal coefficients of expansion which are otherwise highly suitable for use as wear strips (such as ultra-high molecular weight polyethylene) have not been employable as serpentine wear strips.
And even when materials having a low thermal coefficients of expansion are employed as serpentine wear strips, they are expensive to manufacture (as bolt holes most be drilled therein at precise locations along their length), to install (as each wear strip must be individually bolted to each cross member) and to replace (due to the need to unfasten and then refasten the bolts connecting the wear strips to the cross members).
Accordingly it is an object of the present invention to provide a conveyor support way utilizing serpentine wear strips which does not require the bolting of the wear strips to the cross members.
Another object is to provide such a support way which utilizes wear strips formed of a material having a high thermal coefficient of expansion and yet avoids the problems encountered through vertical buckling of the wear strips.
A further object is to provide such a support way in which the wear strips need not be provided with a series of holes therethrough, and are easily installed and replaced without bolting.
Still another object is to provide such a support way which utilizes plastic wear strips and accommodates the thermal expansion and contraction of the plastic wear strips without negative effects.